Protein S-nitrosylation: roles for nitric oxide signaling in the regulation of stress-dependent phytohormones.

Nitric oxide (NO) is integral to modulating a wide array of physiological processes in plants, chiefly through its interactions with phytohormones. This review explores the complex dynamics between NO with four principal phytohormones: abscisic acid (ABA), salicylic acid (SA), auxin, and jasmonic acid (JA). The primary focus is on NO-mediated reversible redox-based modifications with a specific emphasis on S-nitrosylation. The impact of NO-induced S-nitrosylation is profound as it regulates crucial proteins involved in hormone signaling pathways, thereby influencing their synthesis, stability, and functional activity. The review elucidates how NO-mediated S-nitrosylation orchestrates the activities of ABA, SA, auxin, and JA under varying stress conditions and developmental stages. By modulating these phytohormones, NO effectively directs plant responses to a spectrum of biotic and abiotic stresses. This comprehensive review synthesizes current knowledge on highlights the essential role of NO in the regulation of hormonal networks and provides a comprehensive understanding of how S-nitrosylation facilitates plant adaptation and enhances stress resilience.